Rear suspension system for bicycles

Abstract

This application relates to rear suspension system for bicycles, such as freeride, downhill and trail-style mountain bikes. The suspension system includes a rear suspension for coupling the rear wheel of the bicycle to the bicycle frame, a rear shock absorber disposed entirely in front of the seat tube of the frame and a linkage for operatively coupling the rear suspension to the rear shock absorber. The linkage intersects the longitudinal axis of the seat tube for transmitting rear suspension forces around the seat tube to the rear shock absorber. The seat tube is preferably continuous and is disposed so that the bicycle seat is adjustable over a full range of seat positions. The seat tube orientation ensures that the seat is movable between optimum biomechanical positions for both uphill pedaling and aggressive downhill freeriding. Additionally, the seat tube and rear suspension system are configured so that the rear wheel and rear suspension will not contact the seat tube, seat, or bicycle rider even when the rear suspension system is in a fully compressed, forward position. The shock absorber is preferably oriented in an orientation to maximize its stroke length. For example, the shock absorber may be oriented generally parallel to a top tube of the bicycle frame.

1. A rear suspension system for a bicycle having a rear wheel and a frame including a seat tube having a longitudinal axis, said system comprising:
 (a) a rear suspension pivotally coupling said wheel to said frame; 
 (b) a rear shock absorber disposed entirely forwardly of said seat tube; and 
 (c) a linkage coupling said rear suspension to said shock absorber for transferring forces therebetween, wherein said linkage extends in an orientation intersecting a transverse plane passing through said seat tube parallel to said longitudinal axis, 
 
     wherein said linkage comprises a first link pivotably coupled to said shock absorber at a first pivot and a second link pivotably coupled to said frame at a second pivot, wherein said first and second links are operatively coupled together and wherein said first and second pivots are both located forwardly of said seat tube, wherein said second link stably supports reciprocating movement of said first link in a direction intersecting said transverse plane between relatively rearward and forward positions as said rear suspension is adjusted between uncompressed and compressed positions. 
   
   
     2. The suspension system as defined in  claim 1 , wherein said linkage transmits said forces around said seat tube. 
   
   
     3. The suspension system of  claim 1 , wherein said linkage straddles said seat tube. 
   
   
     4. The suspension system of  claim 3 , wherein said linkage comprises first and second spaced apart linkage elements disposed on opposite sides of said seat tube. 
   
   
     5. The suspension system as defined in  claim 1 , wherein said linkage has a length exceeding the diameter of said seat tube. 
   
   
     6. The suspension system as defined in  claim 1 , wherein said rear suspension comprises one or more pivot points and wherein a most forward one of said one or more pivot points is located rearwardly of said seat tube longitudinal axis. 
   
   
     7. The suspension system of  claim 1 , wherein said linkage is pivotably coupled to said rear suspension. 
   
   
     8. The suspension system as defined in  claim 7 , wherein said linkage is pivotably coupled to said shock absorber. 
   
   
     9. The suspension system of  claim 1 , wherein said seat tube is continuous and wherein said shock absorber has first and second ends coupled to said frame forwardly of said seat tube. 
   
   
     10. The suspension system of  claim 8 , wherein said first end of said shock absorber is pivotably to said frame and wherein said second end of said shock absorber is pivotably coupled to said linkage. 
   
   
     11. The suspension system of  claim 8 , wherein said frame is orientable in a vertical frame and wherein said shock absorber has a longitudinal axis extending in a plane at an angle of between 45-90° relative to said vertical plane. 
   
   
     12. The suspension system of  claim 11 , wherein said frame includes a top tube, a head tube and a down tube in addition to said seat tube and wherein said longitudinal axis of shock absorber extends generally parallel to a longitudinal axis of said top tube. 
   
   
     13. The suspension system of  claim 3 , wherein said rear suspension has a four bar suspension design comprising a chain stay link and a seat stay link coupled to said wheel and a rocker arm link coupled to said seat stay link and extending forwardly therefrom. 
   
   
     14. The suspension system of  claim 13 , wherein said linkage is coupled to said rocker arm. 
   
   
     15. The suspension system of  claim 13 , wherein said linkage is coupled to said seat stay link. 
   
   
     16. The suspension system of  claim 13 , wherein said linkage is coupled to said chain stay link. 
   
   
     17. The suspension system of  claim 9 , wherein said frame comprises a top tube, a head tube and a down tube in addition to said seat tube, wherein said front and rear ends of said shock absorber are coupled to said down tube. 
   
   
     18. The suspension system of  claim 1 , wherein said suspension system has a vertical travel range exceeding 5 inches. 
   
   
     19. The suspension system of  claim 18 , wherein when said rear suspension in a fully compressed configuration at its maximum range of vertical travel said rear wheel and said rear suspension are located tangential of said seat tube longitudinal axis. 
   
   
     20. The suspension system as defined in  claim 1 , wherein said linkage comprises at least three separate pivots, wherein at least two of said pivots are located forwardly of said seat tube. 
   
   
     21. A bicycle having a rear wheel, said bicycle comprising:
 (a) a frame orientable in a vertical plane, said frame comprising a seat tube having a longitudinal axis, wherein said seat tube is continuous; 
 (b) a rear suspension for pivotally coupling said rear wheel to said frame, wherein rear wheel is movable within a range of travel between a most rearward position and a most forward position; 
 (c) a rear shock absorber disposed entirely forwardly of said seat tube; and 
 (d) a linkage coupling said rear suspension to said rear shock absorber, wherein said linkage extends in an orientation intersecting a transverse plane passing through said seat tube parallel to said longitudinal axis, 
 
     wherein said linkage comprises a first pivot connected to said shock absorber and a second pivot connected to said frame, wherein said first and second pivots are operatively coupled together and wherein said first and second pivots are both located forwardly of said seat tube, and wherein said frame comprises a down tube and a bottom bracket mounted at a lower end of said down tube for receiving a crank assembly of said bicycle, and wherein longitudinal axis of said seat tube intersects said down tube at a location forward of said bottom bracket. 
   
   
     22. The bicycle of  claim 21 , wherein said linkage transmits said forces around said seat tube. 
   
   
     23. The bicycle of  claim 21 , wherein said linkage straddles said seat tube. 
   
   
     24. The bicycle of  claim 23 , wherein said linkage comprises first and second spaced apart linkage elements disposed on opposite sides of said seat tube. 
   
   
     25. The bicycle as defined in caim  21 , wherein said linkage has a length exceeding the diameter of said seat tube. 
   
   
     26. The bicycle as defined in  claim 21 , wherein said rear suspension comprises one or more pivot points and wherein a most forward one of said one or more pivot points is located rearwardly of said seat tube longitudinal axis. 
   
   
     27. The bicycle of  claim 21 , wherein said linkage is pivotably coupled to said rear suspension. 
   
   
     28. The bicycle as defined in  claim 27 , wherein said linkage is pivotably coupled to said shock absorber. 
   
   
     29. The bicycle as defined in  claim 21 , wherein said shock absorber has first and second ends coupled to said frame forwardly of said seat tube. 
   
   
     30. The bicycle of  claim 29 , wherein said first end of said shock absorber is pivotably coupled to said frame and wherein said second end of said shock absorber is pivotably coupled to said linkage. 
   
   
     31. The bicycle of  claim 30 , wherein said shock absorber has a longitudinal axis extending in a plane at an angle of between 45-90° relative to said vertical plane. 
   
   
     32. The bicycle of  claim 31 , wherein said frame includes a top tube, a head tube and a bottom tube in addition to said seat tube and wherein said longitudinal axis of said shock absorber extends generally parallel to a longitudinal axis of said top tube. 
   
   
     33. The bicycle of  claim 21 , wherein said rear wheel and said rear suspension system are spaced apart from said seat tube in said most forward position. 
   
   
     34. The bicycle as defined in  claim 21 , wherein said longitudinal axis of said seat tube extends at an angle substantially tangential to said most forward position of said rear wheel. 
   
   
     35. The bicycle as defined in  claim 21 , wherein said longitudinal axis of said seat tube extends at an angle between about 50-75° relative to a horizontal plane passing through said seat tube and extending perpendicular to said vertical plane. 
   
   
     36. The bicycle of  claim 24 , wherein said rear suspension has a four bar suspension design comprising a chain stay link and a seat stay link coupled to said wheel and a rocker arm link coupled to said seat stay link and extending forwardly therefrom. 
   
   
     37. The bicycle of  claim 36 , wherein said linkage is coupled to said rocker ann link. 
   
   
     38. The bicycle of  claim 36 , wherein said linkage is coupled to said seat stay link. 
   
   
     39. The bicycle of  claim 36 , wherein said linkage is coupled to said chain stay link. 
   
   
     40. The bicycle of  claim 29 , wherein said frame comprises a top tube, a head tube and a down tube in addition to said seat tube, wherein said first and second ends of said shock absorber are coupled to said down tube. 
   
   
     41. The bicycle of  claim 21 , wherein the vertical travel range of said suspension system exceeds about 5 inches. 
   
   
     42. The bicycle of  claim 21 , wherein the vertical travel range of said suspension system exceeds about 7 inches. 
   
   
     43. A bicycle having a rear wheel, said bicycle comprising:
 (a) a frame orientable in a vertical plane, said frame comprising a seat tube having a longitudinal axis; 
 (b) a rear suspension for pivotally coupling said rear wheel to said frame, wherein rear wheel is movable within a range of travel between a most rearward position and a most forward position; 
 (c) a rear shock absorber disposed entirely forwardly of said seat tube; and 
 (d) a linkage coupling said rear suspension to said rear shock absorber, 
 
     wherein said longitudinal axis of said seat tube extends at an angle substantially tangential to said rear wheel when said rear wheel is in said most forward position, said linkage maintaining said rear wheel and said rear suspension spaced-apart from said seat tube in said most forward position. 
   
   
     44. The bicycle as defined in  claim 21 , wherein said linkage comprises a first link pivotably coupled to said shock absorber at said first pivot and a second link pivotably coupled to said frame at said second pivot, wherein said.first and second links are operatively coupled together. 
   
   
     45. The bicycle as defined in  claim 44 , wherein said first link extends between said rear suspension system and said shock absorber. 
   
   
     46. The bicycle as defined in  claim 45 , wherein second link extends between said first and second pivots. 
   
   
     47. The bicycle as defined in  claim 44 , wherein said first link is pivotably coupled to a rear suspension link at a third pivot, and wherein said rear suspension link is operatively coupled to said frame at a fourth pivot, wherein said third and fourth pivots are located rearwardly of said seat tube. 
   
   
     48. The bicycle as defined in  claim 47 , wherein said first, second, third and fourth pivots comprise a four bar linkage arrangement. 
   
   
     49. The bicycle as defined in  claim 21 , wherein said linkage comprises at least three separate pivots, wherein at least two of said pivots are located forwardly of said seat tube. 
   
   
     50. The bicycle as defined in  claim 44 , wherein said second link stably supports reciprocating movement of said first link in a direction intersecting said transverse plane between relatively rearward and forward positions as said rear suspension is adjusted between uncompressed and compressed positions. 
   
   
     51. A rear suspension system for a bicycle having a rear wheel and a frame including a seat tube having a longitudinal axis, said system comprising:
 (a) a rear suspension pivotally coupling said wheel to said frame; 
 (b) a rear shock absorber disposed entirely forwardly of said seat tube; and 
 (c) a linkage coupling said rear suspension to said shock absorber for transferring forces therebetween, wherein said linkage is adapted to transfer said forces between a location rearward of said longitudinal axis and a position forward of said longitudinal axis, 
 
     wherein said linkage comprises a first pivot connected to said shock absorber and a second pivot connected to said frame, wherein said first and second pivots are operatively coupled together and wherein said first and second pivots are both located forwardly of said seat tube, wherein said linkage comprises a first link pivotably coupled to said shock absorber at said first pivot and a second link pivotably coupled to said frame at said second pivot, wherein said first and second links are operatively coupled together wherein said first link extends between said rear suspension system and said shock absorber, and wherein said first pivot is located rearwardly of said second pivot when said suspension system is in an uncompressed configuration. 
   
   
     52. The suspension system as define in  claim 51 , wherein said first pivot is located forwardly of said second pivot when said suspension system is in a fully compressed configuration. 
   
   
     53. The suspension system as defined in  claim 51 , wherein said first link is pivotably coupled to a rear suspension link at a third pivot, and wherein said rear suspension link is operatively coupled to said frame at a fourth pivot, wherein said third and fourth pivots are located rearwardly of said seat tube. 
   
   
     54. The suspension system as defined in  claim 53 , wherein said first, second, third and fourth pivots comprise a four bar linkage arrangement. 
   
   
     55. The rear suspension system as defined in  claim 51 , wherein second link extends between said first and second pivots. 
   
   
     56. A bicycle having a rear wheel, said bicycle comprising:
 (a) a frame orientabile in a vertical plane, said frame comprising a seat tube having a longitudinal axis; 
 (b) a rear suspension for pivotally coupling said rear wheel to said frame, wherein rear wheel is movable within a range of travel between a most rearward position and a most forward position; 
 (c) a rear shock absorber disposed entirely forwardly of said seat tube; and 
 (d) a linkage coupling said rear suspension to said rear shock absorber, wherein said linkage extends in an orientation intersecting a transverse plane passing through said seat tube parallel to said longitudinal axis, 
 
     wherein said linkage comprises a first pivot connected to said shock absorber and a second pivot connected to said frame, wherein said first and second pivots are operatively coupled together and wherein said first and second pivots are both located forwardly of said seat tube, and wherein said linkage comprises a first link pivotably coupled to said shock absorber at said first pivot and a second link pivotably coupled to said frame at said second pivot, wherein said first and second links are operatively coupled together. 
   
   
     57. The bicycle as defined in  claim 56 , wherein said first link extends between said rear suspension system and said shock absorber. 
   
   
     58. The bicycle as defined in  claim 57 , wherein second link extends between said first and second pivots. 
   
   
     59. The bicycle as defined in  claim 56 , wherein said first link is pivotably coupled to a rear suspension link at a third pivot, and wherein said rear suspension link is operatively coupled to said frame at a fourth pivot, wherein said third and fourth pivots are located rearwardly of said seat tube. 
   
   
     60. The bicycle as defined in  claim 59 , wherein said first, second, third and fourth pivots comprise a four bar linkage arrangement.